Analysis of Hemolymph Ecdysteroids in the Female Earwig: Labidura riparia
Résumé
The nature of hemolymph ecdysteroids was analyzed by high performance liquid chromatography-radioimmunoassay, during the two main phases of the reproductive cycles of Labidura riparia. 20-hydroxyecdysone and ecdysone were present together with polar and apoiar products.
Changes in the ecdysone/20-hydroxyecdysone ratio were evidenced according to the ovarian development. During natural (feeding and sexual phase of the cycle) or induced ovarian development, an increase of the ratio occurred whereas, during ovarian rest (fasting and/or parental phase), a significant decrease was observed.
Up to 40 days after ovariectomy, immunoreactive compounds were observed in the hemolymph which corresponded partly to 20-hydroxyecdysone, ecdysone, and apoiar products. However, a large increase was observed in the proportions of the polar products which were mainly resolved, on the action of Helix enzymes, into 20-hydroxyecdysone and ecdysone.